Method of preparing carotene pigment material



iso-carotene have been described and the existence dide, ither crude or refined, by the addition of 1 aration of carotene has not heretofore been com- UNITED STATES PATENT OFFICE METHOD OF PREPARING CAROTENE PIGMENT MATERIAL Harold M. Barnett, Cleveland, Ohio, assignor to S. M. A. Corporation, Cleveland, Ohio, a corporation of Ghio No Drawing. Application April 12, 1932, Serial No. 604,877

7 Claims. (Cl. 260187) This invention relates to the preparation of a cover the oil practically unchanged, as with palm carotene pigment material, its object being to prooil, should be a material which will not destroy or vide an improved and simple method which can produce harmful effect upon the glycerides. For

be carried out at relatively low cost with the abilexample, I have found that red palm oil, either .3 ity to recover a very large proportion, if not all, crude or refined, may be dissolved in any one of not only of the carotene material, but also of the a-number of petroleum fractions, but the low boilreagents used in the process, and which method ing fractions are the more advantageous because is satisfactory for use in connection with the remore easily removed. Petroleum ether, with a covery of the carotene from oily substances conboiling range of to C. is useful for the tajning t purpose. When the red palm oil is dissolved in pe- A further object is to provide a simple and im-- treleum ether the carotene which is present also proved method of forming or recovering carotene dissolves andany natural or foreign insoluble subiodicle directly from carotene contained in other stances which may be present may be readily re- .material, or, in other words, from a raw product moved by filtration, decantation or the like.

in which the carotene is distributed throughout a To the solution of palm oil in petroleum ether 9 relatively large mass of other material, such as or other solvent I add a suitable reagent for prepalm oil or other natural product. cipitating the carotene and for this purpose iodine As will appear hereafter, the method accomis a suitable precipitant. It is added in proper plishes not only the formation or preparation of quantity and preferably in the form of a finely carotene iodide from such raw materials but it divided solid, such :as finely ground iodine. The .75

also contemplates the removal of the iodine from iodine dissolves in the petroleum ether palm oil such carotene iodide, or, in other words, the solution and coincident with its solution carotene breaking down of the carotene iodide molecule iodide is precipitated and may be removed by filso as to take away its iodine. Such iodine separatration, decantation, crystallization or the like.

25 'tion leaves a substance which if not actually caropeculiar feature of this is the fact that the tene is at least so closely similar thereto as to be, iodine is not absorbed by the oily material, such to all intents and purposes, substantially identical as palm oil, as might be expected, but apparently therewith. The carotene material thus for-med directly combines with, attacks or is absorbed by may involve some slight modification or rearthe carotene, forming the iodide therewith. In

Q rangement as to its molecular structure, but it this manner a-more or less crude carotene iodide nevertheless is substantially identical with cardmay be recovered in-solid form, contaminated only tene in its coloring and pigment-like characterby such palm oil or other fat or impurities as may istics, as well as other characteristics. To avoid be carried down with it. This more or less crude misunderstan in or y p s ina c y, I carotene iodide may be refined in any suitable 3: prefer hereinafter to characterize the product ulmanner, such as by dissolving the solid material 99 timately produced as carotene pigment material in chloroform, reprecipitation with petroleum rather than carotene. This designation is jusether, crystallization, or other suitable steps, as tified by the known existence of several forms of will be readily understood. carotene; thus alpha-carotene, beta-carotene and The iodine is readily removed from the carotene of other forms is D suitable reagents which either absorb it or other- While fr Certain aspects t lnventlon 15 wise dispose of it. Such reagents, for example,

adapted for use in the preparation or separation may be Sodium thio ulfate mercury, ammonium 0f carotene Pigment any supstange hydroxide, alcoholic potash, sodium methylate, containing it, nevertheless it is more particularly Sodium ethylate, etc The final product after adapted for h recovery of i pigment removal of the iodine, is the carotene pigment tenal t g ig 3 i g ggfig g figgg? material before referred to, that is, a substance g g 3 ig i gg l but from which t which is either carotene itself or a substance a e quan 1 y which very closely approximates it, differing if at zlight modification or ract1cab1e all probably only 1n some s igi gg g to my method the raw mater-19,1 Com rearrangement of the molecular structure, but

taining the carotene, such as palm oil, is dissolved nevertheless having subtailtially the ame (30101 in a suitable solvent which is also a solvent for and pigment charactenstics, as well as other carotene and which, in case it is desirable to re- Cha ac st of a e One specific example of the practice of my method is as follows:

Two kilograms of red palm oil are dissolved in about 15 liters of petroleum ether. The solution is cleared by the removal of any solid residue, either undissolved material or solid foreign substances, by filtration or the like. To the resulting solution approximately 12 g. of finely ground iodine are added and the solution is agitated until all of the iodine dissolves. The carotene iodide begins to precipitate almost immediately, and after permitting the solution to stand for several hours the bulk of the supernatant liquid is decanted or siphoned off and the precipitated carotene iodide is separated from the remainder of the solution by filtration or any other suitable method. Depending upon the amount of fat and other impurities carried down with the iodide, and also upon the amount of carotene originally present in the palm oil, it is found that from 5 g. to 15 g. of crude carotene iodide may be obtained in this way. The crude carotene iodide may be refined by dissolving the solid material in chloroform and reprecipitating the iodide with petroleum ether, or, it may be treated directly with one of the reagentsmentioned above, such as sodium thiosulfate, for the removal of the iodine and the recovery of the carotene pigment material.

About 90% of the solvents used may be recovered from the palm oil by distillation. Some free iodine may distill with the solvent, such as with the petroleum ether, but this in no way hinders use of the recovered solvent in subsequent treatments of further palm oil for the separation of carotene therefrom. The removal of the solvent further leaves a residue of crude palm oil which may be used for any other purposes, and if desired, the small amount of free iodine remaining in such recovered palm oil may be readily removed by shaking with sodium thiosulfate solution.

The quantityof petroleum ether or other solvent to palm oil may be Varied within reasonable limits. Either too much or too little with respect to the palm oil may reduce the yield of carotene iodide, and if the ratio is too low the separation of the carotene iodide may also become more difficult.

The methodv described provides a very simple way of removing in concentrated form a very large proportion of the carotene present in palm oil or like oily substances containing it, with the possibility of also recovering a large proportion of the reagents employed in the process, such as petroleum ether or other petroleum fractions or other solvents, as well as the palm oil, and not only enables such carotene to be prepared as the iodide from a more or less crude material, but also provides for the preparation of the carotene pigment material from the iodide.

What I claim is:

l. The method of recovering carotene pigment substance from raw materials containing the same and consisting mainly of glycerides, comprising dissolving the material in a solvent therefor and precipitating carotene iodide therefrom.

2. The method of separating carotene pigment material from naturally occurring glycerides containing the same, consisting in dissolving the glycerides in a solvent and precipitating carotene iodide therefrom.

3. The method of separating carotene pigment material from palm oil by dissolving the oil in a solvent, adding iodine thereto and collecting the resulting precipitate.

i. The method of separating carotene pigment material from oily materials consisting mainly of glycerides, consisting in dissolving the material in a solvent, precipitating and collecting carotene iodide, and removing the iodine therefrom by treatment with a reagent for iodine.

' 5. The method of recovering carotene pigment material from naturally occurring glycerides containing it, consisting in converting the carotene to carotene iodide, separating the latter,

and splitting off the iodine therefrom by treatment with a reagent for iodine.

6. The method of preparing carotene pigment material from palm oil, consisting in dissolving the palm oil in a solvent, adding free iodine containing material thereto, thus precipitating the carotene as an iodide, and recovering the carotene pigment material from the iodide by treatment with a reagent for iodine.

'7. The method of preparing carotene pigment material from palm oil, consisting in dissolving thepalm oilin a solvent, adding solid iodine to the solution, separating the precipitated carotene iodide, and treating the latter with sodium 'thiosulfate to recover a carotene pigment material.

HAROLD M. BARNETT. 

